There are certain machines on the market equipped with manually operable levers and the like that are manipulated at one time or another between different operational positions, or between an operative position and an interim position. For some of such machines, it is undesirable to perform certain phases of an operation with the lever in a specific position. Unfortunately, when no alarm unit is built into such a machine or apparatus, the operator often forgets to restore the lever to the proper operative position, thus resulting in faulty performance of the machine.
Illustrative of this type of situation is the widely-used Computer Printer manufactured by International Business Machines, designated the 5203 Printer, although my invention is obviously not to be limited to use with such a machine. The IBM Computer Printer utilizes continuous form computer paper, with it being necessary from time to time to replenish the supply of paper in the machine, or to change to a different form or type of paper. In order to do so, it is necessary to release a portion of the machine, known as the rear unit, from the closed position, and tilt it rearwardly, away from the operator. It is further necessary to disengage the clutch associated with paper movement to permit alignment of the forms after replenishment or substitution of paper, but unfortunately, the typical operator from time to time forgets to re-engage the carriage clutch after the paper loading operation has been completed, and the rear unit returned to the closed position. In the instance at hand, the carriage clutch mechanism is engaged or disengaged by a small finger-operated lever disposed on the carriage clutch unit of the machine. The finger operated lever, known as a space select lever, has left and right operational positions, with the left operational position providing printing at 6 lines per inch, and the right operational position providing printing at 8 lines per inch.
The center position for this lever is a carriage clutch disengaging position, and it is to this position that this lever must be moved to allow for proper alignment after the paper has been reloaded in the machine. No warning device is presently associated with the space select lever, and it is therefore easily possible for the operator to fail to move this lever away from the center or interim position, back into an operative position, when the reloading operation has been accomplished. The consequence of a failure to move the lever back into an operative position is that the paper does not move through the machine, and the machine will continue to print at a single location on the paper, with this pile-up of printing obviously resulting in completely unintelligible words.
When this event happens, the difficulty is not completely remedied merely by moving the finger-operated lever to one or the other of the operative positions, for the machine must be reset and restarted so that the overprinted material can be rerun. It is quite apparent that the failure to reset the finger-operated space select lever to an operative position can become quite expensive when it is realized that the typical rerun of a job involves operator salary, machine and materials cost, and overhead.
It is to prevent oversights of this type that I have evolved the instant Alarm Unit which, despite its low cost, is quite effective in reminding the operator to engage the carriage clutch of the associated machine before placing it back in operation after a paper reloading cycle, or a paper alignment adjustment.